Kidney cysts may be congenital (associated or not with genetic disorders) or rarely acquired. They may be an isolated abnormality or be part of an anomaly syndrome. The aim of the study was to analyse the history of patients with suspected/diagnosed cysts of the kidney(s) admitted to the authors’ department in 2015–2016. Material and methods: In this period 1,604 patients were hospitalised, including 49 children aged 1 month – 17 years with a suspected/diagnosed cyst of the kidney(s). There were 30 first-time admissions and the remaining cases were repeat admissions. Results: There were 14 infants (mean age of 4.2 months) among the children hospitalised for the first time. The final diagnoses in this group were as follows: autosomal recessive polycystic kidney disease in 3 children, autosomal dominant polycystic kidney disease in 1 child, right multicystic dysplastic kidney in 4 children, right multicystic dysplastic kidney combined with left ectopic kidney in 1 child, bilateral multicystic dysplastic kidney in 1 child, single renal cysts in 2 children and renal cystic hypodysplasia in 2 children. Among the remaining 16 children (mean age of 10.1 years) diagnosed for the first time due to arterial hypertension or abnormalities on abdominal ultrasound imaging, autosomal dominant polycystic kidney disease was found in 11 children, right multicystic dysplastic kidney in 4 children and left multicystic dysplastic kidney in 1 child. Among 19 patients hospitalised more than once (mean age of 9.5 years) autosomal dominant polycystic kidney disease was diagnosed in 4 children, autosomal recessive disease in 6 individuals, right multicystic dysplastic kidney in 4 children, left multicystic dysplastic kidney in 3 children and other forms of cystic kidney disease in 2 children. In 23 children (47%) various stages of chronic kidney disease were found and in 3 patients a renal transplant was performed. Conclusion: Renal cysts are not a common reason for hospitalisation at a pediatric nephrology centre (3.1% of patients); however, they do require diagnosis and monitoring of patients due to the risk of development of chronic kidney disease.